1. Field of the Invention
The invention relates generally to the field of endotracheal intubation, and more particularly, to an endotracheal tube guide especially useful in facilitating nasotracheal intubation of patients under either direct vision laryngoscopy or blind techniques.
2. Description of the Prior Art
The intubation of patients is a technique well known in the anesthesia and medical arts and involves the insertion of an endotracheal tube into the trachea through either the nose or mouth. In the direct technique, the tip of the endotracheal tube is observed with a laryngoscope as the tube progresses down the posterior pharynx into the glottis, through the vocal cords and into the trachea. During nasotracheal intubation, it is often necessary to guide the endotracheal tube into the glottis with the aid of forceps. In intubation of this type, the visible end of the endotracheal tube is grasped with the forceps, and the practitioner controls the direction of the tip of the tube in order to guide it into the glottis and through the vocal cords.
In the blind technique, the tube direction is changed by flexion, extension, or rotation of the head, as the blind application of forceps is extremely hazardous and is of no value in facilitating blind intubation.
U.S. Pat. No. 3,701,348 to Navara discloses a tool used for pathological procedures, such as the opening of the skull. To this end, the device of Navara is provided with a relatively flat elongated center portion, a flat chiseled portion formed on one end of the center portion, and a curved retractor portion formed on the other end of the central portion. As seen in FIG. 1 of the patent, the retractor portion 17 comprises an inwardly curved member and is of about the same length as the chisel portion 15. In use, a cut is made in the skull by a suitable high velocity saw. The chiseled portion 15 is inserted into the groove made by the saw blade, and is then laterally moved to separate the parts of the skull by prying. The retractor portion 17 is then used to hook an edge of the severed portion, and to remove the same. However, while the device disclosed by Navara may have certain utility as a skull retractor, it is much larger than anything which would be usable for tracheal work.
The V. Mueller & Co. Catalogue (1929) at page 232 discloses two types of retractors for use in tracheal work. The retractor A8535, known as Shurly's retractor, consists merely of a flat length of sheet steel with a bend in one end. This type of retractor has distinct disadvantages in that the central gripping portion thereof is wide and flat and is, therefore, difficult to delicately manipulate by the practitioner. Further, as the handle portion of this retractor is straight, rather than angled, the hand which normally grips and guides the retractor will necessarily often obstruct the view of the user. Model No. A8540 of the same catalogue shows a retractor which has a long slim tapered handle which allows for easy manipulation by the user. However, as the handle portion is straight, the user's hand will still often block a direct view of the endotracheal tube. Further, the tube engaging portion of this retractor is formed generally in the shape of a common fork, with the tines curled around in order to make a scoop-like shape. Thus, this retractor is extremely unsuitable for use in the blind technique, as the sharp tips of the tines are likely to engage and tear the tissue surrounding the area adjacent the endotracheal tube.
The Scanlon-Morris Co. Brochure (Stille Division) discloses at pages 2, 3 and 4 thereof a plurality of retractors for geneal use. The Model No. 86-54 retractor is disclosed as being for tracheal use. However, the design of this tracheal retractor is very similar to the previously mentioned Mueller retractor in that the endotracheal tube-engaging portion is provided with sharp tips and is, therefore, of no utility in a blind intubation technique. The Model No. 46-88retractor is a large liver retractor having a hollow handle.
The Murray-Baumgartner Surgical Instrument Co. Catalogue (1934) again discloses a plurality of retractors for general surgical use. Of particular interest are the Model Nos. 2149-2152 which display a curved scoop-shaped retractor blade portion. However, it is noted that the handles of these retractors are thin, flat, and of an overall arcuate shape and, therefore, have the same disabilities for delicate work as do the previously mentioned Mueller retractors.
The Charles Truax Greene & Co. Catalogue depicts a plurality of retractors for use in gynecology. FIG. 7233 of this Catalogue depicts a retractor which has a generally scoop-shaped end. However, the handle of this retractor does not allow the practitioner to grip and manipulate the device in a manner such that the practitioner's hand would not obstruct his view of an endotracheal tube.
The Journal of the American Medical Association, July 12, 1952, contains an article on pages 1018 and 1019 thereof which discusses the use of various types of generally S-shaped retractors formed of lucite. However, it is noted that none of the retractors disclosed in this article has a blade having upper and lower blade portions whose junction is attached to a thin elongated generally cylindrical gripping portion.
The Codman General Surgical Instruments Catalog, cover page, and pages 83 and 193 (1973) relate to an atrial retractor, not to an endotracheal tube guide. Atrial retractors are used to retract the atrium during cardiac surgery. The extremely large handle of the atrial retractor of FIG. B is used so as largely to eliminate arm and finger fatigue in the surgeon using the retractor for extended period of time. A constant pull with a minimum amount of movement is required in the use of such retractors, and the manipulability of the retractor is not of primary importance. In the retractor of FIG. A of page 193, the handle portion is knurled so as to allow the surgeon firmly to grip the instrument, but, again, the manipulability of the instrument is not of primary importance.
USSR Patent No. 182293 shows a surgical instrument having a double bend in the handle thereof for facilitating visual observation during intra-aural operations.
The publication, Anesthesiology, volume 51: 274, 1979 contains on page 274 thereof a disclosure of applicant's endotracheal tube retractor which is the subject of the above cross-referenced copending patent application. This retractor cannot easily guide an endotracheal tube in the posterior direction. Furthermore, the retractor handle must be rotated to guide the endotracheal tube in a right or left lateral direction. This maneuver may occlude the field of vision in some instances.